/*
    Carracci Systems - Carracci Server (openbam project)
    Copyright (C) 2007  Carracci Systems

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/


package org.openbam.core.expr;


/**
 * @author inder
 */
public class Concat extends BinaryExpression implements IFunction {


    public Concat() {
		super.setName("Concat");
	}

	protected Object operate(Object lhsValue, Object rhsValue) {
        if (lhsValue == null && rhsValue == null) {
            return null;
        }
        
        StringBuilder builder = new StringBuilder();
        builder.append(lhsValue != null ? lhsValue : "").append(rhsValue != null ? rhsValue:"");
        return builder.toString();
    }

    public IExpression newInstance() {
        Concat concat = new Concat();
        concat.lhs = this.lhs;
        concat.rhs = this.rhs;
        return concat;
    }
}
